Study of Microstructural Effects in the Strength of Alumina Using Controlled Flaws

Abstract

Strength characteristics were studied as a function ofVickers indentation Load for aluminas with two grain sizes. At low loads the strengths tend to well‐defined plateaus, the levels of which bear an inverse relation to grain size. These trends are consistent with a trunsition from indentation‐controlled to microstructure‐controlled behavior as flaw size diminishes. The conventional indentation fracture formalism was modified to account for this transition.